Vapor fusing apparatus



Nov. 2, 1965 H. E. CLARK 3,215,116

VAPOR FUSING APPARATUS Filed Aug. 15, 1962 2 Sheets-Sheet l INVENTOR. 3HAROLD E. CLARK A 7'7' ORNE Y Nov. 2, 1965 H. E. CLARK 3,215,116

vAPoR FUSING APPARATUS Filed Aug. 15, 1962 2 Sheets-sheet 2 INVENTOR.HAROLD E. CLARK United States Patent O 3,215,116 VAPOR FUSING APPARATUSHarold E. Clark, Penlield, N.Y., assignor to Xerox Corporation,Rochester, N.Y., a corporation of New York Filed Aug. 15, 1962, Ser. No.217,027 7 Claims. (Cl. 118-637) This invention relates to improvedapparatus for fusing powder images onto the surface of support material.More particularly, the invention relates to xerography and to apparatusfor vapor fusing .of powder images loosely formed Xerographically onto acontinuous support web.

In the process of xerography, as first disclosed, for example, inCarlson Patent U.S. 2,297,691, a previously formed electrostatic latentimage on the surface of a xerographic plate is rendered visible bydeveloping with a powder deposited on the plate surface. Commercialforms of powder used for developing are usually of a pigmented resinsuch as disclosed in Rheinfrank et al. Patent U.S. 2,788,288 and CarlsonPatent U.S. Reissue 25,136. The powder image t-hus formed is then aiixedto the surface upon which it has been deposited or onto the surface ofanother support material to which it may have been transferred bytechniques known to those skilled in the art.

Conventionally there are two usual methods by which a powder image isiafiixed. The first of these methods is with the application of heat inwhich case the powder image or its support must be formed of athermo-responsive material, such as a heat fusible resin, which iiowswithout image distortion when heated and coalesces when cooled tolambient temperature. The second of these methods is to introduce theimagebearing support material into an atmosphere of the vapor of asolvent for the developing powder as disclosed in Carlson Patent U.S.2,776,907. In the solvent vapor process, the powder image is rendered atacky cohesive mass while in the presence of the atmosphere of thesolvent vapor and usually while still tacky is removed to ambient airfor evaporation of the solvent, leaving the image bonded to the supportmember. The solvent vapor process is referred to in the art as vaporfixing.

While heat fusing has been put to wide scale commercial use in automaticmachines, it is recognized that improvements are possible. For example,most commercially marketed machines employ a thin layer of vitreousselenium as the photoconductor. Continuous heat exposure is known tohave a deleterious effect on the photoconductive properties lofselenium. Dissipation or insulating of the heat, therefore, must becarefully controlled. When the image is to be fused to paper, celluloseacetate, or other base having a relatively low charring or combustiontemperature, as is usually the case, the powder must be made of materialwhich becomes adhesive `at a temperature below that which will causedamage to the base. This imposes limitations on the choice of resinswhich make it difficult to meet other desirable characteristics in thepowder composition. Furthermore, certain paper stocks, such as used inrecord controlled accounting cards, have controlled moisture contentswhich are decreased at high temperature destroying cards for theirintended purpose. Moreover, it has become diilicult to reach an entirelysatisfactory design of heat fuser with regard to a short warm-up time,low electric current requirements, adequate heat insulating and uniformheat distribution particularly at high operating speeds without theattendant disadvantage of fire hazard associated with fusers employingheat as the fusing media.

,. ICC

Vapor fixing of powder images by means of a solvent vapor has also beenput to a practical use and found to form dense, blacker images thanformed by heat fusing. However, most solvents suitable for use inconjunction with these resins generally used in toners are characterizedby various orders of undesirability such as obnoxious odor, toxicity,etc. For example, one such solvent found particularly suited for fusingxerographic images is tr1- chloroethylene, which happens to becharacterized by objectional odor and a degree of toxicity which canraise to an objectionable level if allowed to escape to the room at ahigh rate.

Operation of vapor fusing devices heretofore has 1neluded removal oremergence of the image-bearing support surface from the vapor chambersuch that the support surface contained not only absorbed vapor but alsowas accompanied by vapor dragout, i.e., a layer of solvent vaporaccompanying the moving support surface. rThis dragout not only hascontributed to the inefficiency of the system but its effect on airdilution has caused general uncomfortableness for the operators of theapparatus in attendance not to mention the inherent toxic dangers. Wherethere is likely to be large volumes of copy to be fused, as is usualwith automatic xerographic machines operated continuously, expensive andbulky ventilation equipment has been required to avoid atmosphericcontamination.

Apparatus, therefore, employing trichloroethylene as a fusing solvent,and vapor fusing in general has encountered restricted and intermittentuse and has generally been employed only on low volume output equipment.

Now in yaccordance with the instant invention, there is providedimproved apparatus employing solvent vapor for continuous fusingoperation particularly suited for automatic xerographic apparatus withcontinuous web support members and adapted for high speed operation.

It is, therefore, an object of the invention to provide novel apparatusfor vapor fixing of powder images onto surfaces of continuous supportmaterial on which the powder image is loosely supported.

It is a further object of the invention to provide improved vapor xingapparatus for continuous xing of the xerographic powder images to movingsupport material.

It is a further object of the invention to achieve vapor fixing ofxerographic powder images .onto a continuous support web by improvedapparatus resulting in substantially reduced solvent consumption andvapor dnagout as compared to other such devices of the prior art.

It is a further object of the invention to provide novel vapor fusingapparatus for a continuous web in which vapor dragout to ambientatmosphere is `substantially eliminated.

These and other iobjects will appear clearly in the followingspecilication when read in connection with the drawings, the novelfeatures being pointed out in the claims at the end of thespecification.

In the drawings:

FIG. l is a schematic arrangement of an automatic xerographic apparatusincorporating one embodiment of the fuser apparatus of the invention;

FIG. la is a front View of the door mechanism of FIG. l;

FIG. 2 is an isometric view of a second embodiment of fusing apparatusin accordance with the invention; and,

FIG. 3 is a sectional elevation through the embodiment illustrated inFIG. 2.

For a general understanding of the xerographic process ing system bywhich the invention is being illustrated, reference is had to FIG. l inwhich the various system components :are schematically illustrated. Asin most xerographic systems based on the concept disclosed in the iabove-cited Carlson patent, a light radiation image of copy to bereproduced is projected onto the sensitized surface of a xerographicplate to form an electrostatic latent image. Thereafter, the latentimage is usually developed with oppositely charged developing materialto form a xerographic powder image, corresponding to the latent image,on the plate surface. In one common system of the reusable type, i.e.,one in which the xerographic plate is recycled, the powder image is thengenerally electrostatically transferred to a support surface to which itis usually fused by a fusing device causing the image to permanentlyadhere to the support surface.

In another well known type of system utilizing an expendable type plateas, for example, a commercially marketed plate of zinc oxide in asuitable binder on a exible support, the powder image is formed andfused directly thereon. Therefore, for purposes of illustration, theinvention will be described in connection with the reusable type ofxerographic plate in which the transferred image i-s to be fused to asecondary support surface. lt is to be understood, however, that thefusing apparatus of the invention has utility with any form of websurface on which the image is contained including the expendable typexerographic plate.

The xerographic apparatus described herein typically may be of the typedisclosed in copending application, Serial No. 837,173, led August 31,1959, in the names of A. J. Cerasani et al., now Patent U.S. 3,076,392.Opaque copy to be reproduced is placed on a support tray 10 from whichit is fed onto a transport mechanism generally designated 11. Suitabledrive means are provided for the transport mechanism from motor 12 toendless belts 13 whereby copy is moved past the optical axis ofprojection lens system 14 and illuminated by a projection lamp LMP-1.The image of the copy is reflected by mirror 15 through an adjustableobjective lens 16 and then reflected by mirror 17 downwardly through avariable slit aperture assembly 18 and onto the surface of a xerographicplate inthe form of drum 19.

Xerographic drum 19 includes a cylindrical member mounted in suitablebearings in the frame of the machine and is driven in a clockwisedirection by a motor 24 at a constant rate that is proportional to thetransport rate of the copy, whereby the peripheral rate of the drumsurface is identical to the rate of movement of the reflected lightimage. The drum surface comprises a layer of photoconductive material ona conductive backing that is sensitized prior to exposure by means of acortona generating device 25 energized from a suitable high potentialsource.

The exposure of the drum to the light image discharges thephotoconductive layer in the areas struck by light, whereby thereremains on the drum a latent electrostatic image in image configurationcorresponding to the light image projected from the copy. As the drumsurface continues its movement, the electrostatic latent image passesthrough a developing station 26 at which a twocomponent developingmaterial 27, which may be of the type disclosed in US. Patents 2,618,552and 2,638,416, is cascaded over the drum surface by means of developingapparatus 28 which may be of the type disclosed in copendingapplication, Serial No. 393,058, led November 19, 1953, in the names ofC. R. Mayo et al.

In the developing apparatus, developing material is carried by conveyor29 driven by suitable driven means from motor 30 and is released ontochute 31 and cascades down over the drum surface. The toner component ofthe developer is partially consumed in developing. Additional toner 32is stored in dispenser 33 and is released in amounts controlled by gate34 to the developer to replenish and assure uniform development.

After developing, the xerographic powder image passes a dischargestation 41 at which the drum surface is illuminated by a lamp LMP-2,whereby residual charges on the non-image areas of the drum surface aredischarged. Thereafter, the powder image passes through an imagetransfer station 42 at which the powder image is electrostaticallytransferred to a support surface web 43 by means of a second coronagenerating device 44.

The support surface to which the powder image is transferred may bepaper, vellum, card stock, etc., that is, continuous and as statedabove, may optionally comprise an expendable continuous type xerographicplate on which the powder image is directly formed. The support surfaceis obtained from a supply roll 45 and is fed over suitably groundedguide rolls 46 and 47, and over suitable tensioning rolls being directedinto surface contact with the drum in the immediate vicinity of transfercorona generating device 44. After transfer, the support surface isseparated from the drum surface and guided into the fusing apparatus ofthe invention 50, to be described, whereby the powder image ispermanently affixed to the support surface. In most known commercialmachines of the type being described, the fusing apparatus has been ofthe heat fusing type as, for example, disclosed in Crumine Patent U.S.2,852,651.

After separation of the support surface from the drum, a coronagenerating device 54 may direct negative electrostatic charge to theresidual powder image on the drum surface. Thereafter, the xcrographicdrum surface passes through a cleaning station 55 at which its surfaceis brushed by a cleaning brush assembly 56, rotated by a motor 57,whereby residual developing material remaining on the drum is removed.The drum surface then passes through a second discharge station 58 atwhich it is illuminated by a fluorescent lamp LMP-3, whereby the drumsurface in this region is completely flooded with light to remove anyelectrostatic charge that may remain thereon. Suitable light traps areprovided in the system to prevent any light rays from reaching the drumsurface, other than the projected image, during the period of drumtravel immediately prior to sensitization by corona generating device 25until after the drum surface is completely passed through the developingstation 26.

Referring now to the fuser apparatus there is illustrated the apparatusof the invention in which a vapor of a solvent for the solvent solublecomponent of the powder image is effective to amx the powder image tothe support web. The solvent employed must of necessity be an easilyvolatilized solvent for the material constituting the powder image andfor obvious reasons should be nonexplosive. The particular solventemployed depends on the properties of the particular image materialand/or base on which the image is to be supported. Trichloroethylene isone solvent particularly suited for image material of the type referredto above. Other suitable solvents include chloroforrn, carbontetrachloride, and other chlorinated solvents; the various Freons(believed to be fluorinated lower alkalines); aromatic and aliphatichydrocarbons Stich as benzene, toluene, gasoline and gasoline fractions;oxygenated solvents such as ethanol, acetone, ethyl acetate and otheralcohols, ketones, esters and the like. In all cases, the particularsolvent is appropriately selected for the particular combination ofmaterial compositions employed.

The various solvents are characterized by various degrees of toxicityand the problems of minimizing dilution 1n the ambient atmosphere shouldbe appreciated. The following list taken from various handbooks such asthe Handbook of Organic Industrial Solvents, published by the NationalAssociation of Mutual Casualty Companies, indicates a summary ofallowable maximum concentrations in the atmosphere of sample solvents tomaintain the atmosphere below unsafe levels of toxicity. Theconcentrations are expressed in parts per million (ppm.) and as listedinclude trichloroethylene at 200 ppm.; chlorethene at 500 ppm.; Freon112 at 1000 p.p.m.; Freon 11 at 1000 ppm.; and Inhibisol at 500 ppm.These solvents have each been found to accord various degrees of fusingwhen used in conjunction with developer of a type described, forexample, in Patents 2,618,552; 2,638,- 416; 2,659,670; 2,753,308;2,788,288; 2.892.794 and Reissue 25,136 as well as commercially marketedproducts such as 914 Copier Toner which is a trademark of XeroxCorporation of Rochester, New York. It is not intended, however, thatthe named solvents should in any way constitute a limitation relevant tothe instant invention.

The fuser apparatus, as illustrated in FIGURE 1, is comprised of abox-like structure forming a vapor charnber 70 into which the web 43 iscontinuously passed for windup onto take-up roll 52 shown completelyenclosed in the chamber. The chamber is constructed substantiallyvapor-tight, and is formed of a front wall 71, side walls 72 and 77 andbottom, top, and rear Walls 73, 74 and 75, respectively. Defined infront wall 71 is a narrow opening 76 through which the web enters thechamber.

The take-up roll is mounted on an axle 60 journaled for rotation betweena pair of parallel extending arm supports 62 secured at their oppositeend to a shaft 67 journaled in the side walls. The shaft 67 is undercontrol of a rotary solenoid 68 which when energized causes the take-uproll to be supported within the chamber. When de-energized, as formachine shutdown, the solenoid causes the arms to rock to the positionshown dotted against a bumper 69 passing the take-up roll through atwo-way swinging split door 64.

The door is made up of two separate sections each secured via a springhinge 65 to front wall 71 and which contain overlapping flexible sealmembers 123 and 124 of silicone impregnated fiber glass strips toprovide a substantially vapor tight joint along the line of contact.Each door section is separately comprised of two individual sectionshinged together via a spring hinge 122 to permit the roll to passthrough the door free and clear after which the door snaps back to closeoff the chamber. Additional seals 125 secured to the front wall alongthe side edges of the door sections further prevent the escape of vaporduring operational periods. Openings 126 and 127 in the top section eachcovered by a split seal 127 permit arms 69 to protrude through the door.On startup, as the take-up roll is positioned for operation, the doorsare caused to swing inwardly before snapping into their closingposition. By this means, excessive solvent absorption in the web as wellas vapor escape to the ambient atmosphere is prevented in the event of apower failure or other machine shutdown.

Rotation of the take-up roll is effected via a motor 53 through aslip-clutch 63 adapted to maintain Windup at a uniform linear speed.Actual connection is via a belt, not shown, that becomes slack when thetake-up roll is advanced out of the chamber by the arm supports 62.

Supported on a shelf on the bottom Wall is a reservoir 80 for containingliquid solvent 81 for the solvent soluble component of the powder imageto be fused. Since a `certain quantity of solvent is consumed in theprocess of fusing, the level of liquid solvent is maintainedsubstantially level and constant by means of makeup solvent contained ina dispenser bottle 82 which flows solvent to the rreservoir 80 viaconduit 83 connected to the reservoir 8i) below the liquid level.

The generation of vapor within the chamber is effected by means of asolvent wick 9i) formed of felt, cloth, blotting paper or the like. Thelower end of the wick is rolled into a wad at the bottom of thereservoir to draw up solvent in the wick and generate a vapor atmospherealong the path of movement of web 43 moving therepast. Preferably,although not necessarily, the wick is arranged and supported to besubstantially parallel or otherwise contoured to the path of webmovement from the vicinity of opening 76 to the vicinity of its winduponto the take-up roll.

Therefore as the web continues to advance from transfer station 42 onapproaching the fuser apparatus 50, it passes first through opening 76,then over guide roll 92 and then up onto the take-up roll 52. From thetime of entering the chamber and while still being wound onto thetake-up roll, the web is caused to be exposed to a saturated atmosphereof the vapor of the solvent 82.

As can be seen7 the web passes with the image bearing surface facingtoward the Wick member to effect maximum exposure to the vaporizedsolvent.

As the web winds onto the take-up roll, it does so in spiral-likefashion with each added layer of periphery overlapping against thepreviously added layer. After a predetermined length of web has beenwound, the unit can be stopped as by interrupting the operation and theroll is automatically removed out from the chamber by the action ofsolenoid 68 through the door 64 outwardly against the tension of pivot65. Alternatively, an opening can be provided in the front wall throughwhich the wound roll can be unwound directly in place and severed intodesired length usually corresponding to dimensions of the reproductionscontained thereon.

Whereas it would be expected that `the powder image, softened byexposure to the vapor atmosphere of the solvent from the solvent solublecomponent of the powder image, would continue on windup to absorbsolvent to become increasingly soft as to offset onto a surface againstwhich it came into contact, it has been found in accordance with theinvention that surprisingly little and only a negligible amount of thesoftened powder does,.in fact, offset. This has been found to be truefor either line copy or continuous tone subjects throughout a wide rangeof operating speeds up to about twelve inches per second. Some variationwas found to exist dependent on the texture of surface with the roughertexture papers according lower offset. In any case, the amount ofoffsetting was found not to smear the image or damage the paper in anyWay. At the same time, a strong fused bond resulted between the powderimage and the web. By this means, therefore, it was found possible tooperate the web at speeds in the range of from virtually ze-ro up to onthe order of twelve inches per second and above without significantoffsetting between adjacent overlapping layers of a wound web, and inall cases, without any smudging of the image previously formed.

On unwinding the web in order to effect severing for its ultimatedisposition, it was found that relatively little ventilation wasrequired as compared to such prior art devices, since only vaporabsorbed by the web and the powder released into the atmosphere ascompared to the larger amounts of vapor of the prior art devices thatincluded both dragout and the absorbent release. Thus, by the instantinvention, the solvent consumption per unit of copy has been found to besubstantially reduced having completely eliminated the effect of vapordragout. This has resulted in a more ecient, more economical and yethigher speed vapor fusing method and apparatus as compared to any knowndevices of the prior art.

Referring now to FIGS. 2 and 3, there is illustrated a variation of theapparatus as described above in connection with FIG. 1. In thisembodiment, take-up roll 52 supported on axle 60 is driven via a motor85 which through gears 86 and 87 drives a timing belt 88 engaging pulley89. The pulley is secured to a shaft end of a slip clutch 99. A shaft91, extending from the clutch, is journaled for rotation in support 93and has a splined end to receive the axle 60. The take-up roll in thisembodiment is adapted to be exposed at least partially exterior of thechamber at a relatively large opening 94 in the front wall. The webenters near the top of the opening adjacent a lip 95 and then isdirected past a wick similarly as above being stretched across theopening onto the take-up roll. In order further to maintain the chambersubstantially sealed against leakage of vapor to the surroundingatmosphere, one end of the roll abuts the side wall 77 while a guideplate 101 having a turned end ange 109 supports the axle and abuts theother end of the roll. The guide plate is positioned by means of a crankhandle 113. Since the vapor generated in the chamber is substantiallyheavier than air, it tends to settle towards the bottom of the chamber.

In order to provide a vapor seal along the bottom of the take-up roll,there is provided a roller 96 adapted to contact lightly against theimage-bearing surface of web 43 being wound on take-up roll 52. Theroller is mounted for rotation in a bracket 97 in turn mounted on a pairof pistons 98 each adapted for vertical movement in guideways 102 angemounted on a shelf plate 112. The pistons are urged upward to urge theroller against the web being wound by means of resilient, compressed,light tension springs 103. By this means, the roller 96 is always incontact against the drum surface but as the roll diameter increases, byvirtue of the winding of the web, roller 96 is caused to move downwardagainst the urgence of the springs.

To prevent offsetting of the image material to the roller 96, itsperiphery contains or is formed of an adhesive material such as Teflonto which a thin coating of silicon oil may be dispensed from adispensing roll 110 also supported in bracket 97. A manifold orreservoir 104 having a plurality of uniformly spaced separate dispensingnozzles 107 dispenses oil 111 through tubing 105 and a control valve 106to the drip nozzle 107. The oil drips onto roll 110 and uniformlydistributes itself over the periphery during rotation thereof and isthen presented into contact against the peripheral surface of roll 96. Adrip pan 108 collects excess oil off roll 110. By this means, asubstantial vapor seal is effected along the underside of the take-uproll without smudging the image being contained thereon.

When using the fuser for excessively high speeds of operation, anauxiliary heater 116 may be provided. The heater is supported on abracket 120 pivotally mounted on a rod 121 so that the heater can beplaced into operative or inoperative relation relative to the websurface on the roll. The heater is comprised of radiant coils 117energized from a potential source 118 and is adapted to heat the web andevaporate absorbed solvent contained on the web and its image prior toits being overlapped upon during its windup onto the take-up roll. Asuitable blower may be provided to carry off vaporized solvent,vaporized by the effect of heater 116.

For removal of the take-up roll 52 from the chamber, axle 60 iswithdrawn to disconnect from shaft 91 after which take-up roll 52 may beraised from its mounting. Optionally, web 43 wound on roll 52 may beunwound from the chamber directly in place and severed into prescribedlengths as required.

It should be apparent that the size of elements may be controlled byvarious factors including web dimensions,

solvent employed, rate of web movement, developer comy position, etc.,in order to achieve a required vapor eX- posure prior to overlapping theweb. Minimum width of the chamber may be a function of web widthalthough wider fusers may be employed with narrow webs while height andpath length within the chamber may be controlled by solvent, speed oftransport, developer material or the like. Typically, it has been foundthat for an eleven inch web at speeds of 20 feet per minute, employingdeveloper as described in Carlsons Reissue 24,135 and withtrichloroethylene as the solvent, images fuse in about 11/2 seconds ofexposure before being overlapped onto the take-up roll. The materials ofconstruction for the various elements should preferably not be subjectedto chemical attack for the solvent employed. For trichloroethylene,various materials such as stainless steel or nylon have been foundsuitable.

By means of the invention, therefore, there is provided high speedapparatus for vapor fusing xerographic powder images onto a continuoussupport web on which substantially only that solvent absorbed in theimage material and to a minor degree, the web, if of an absorbentmaterial, ever leaves from the chamber. It is to be noted that heat, ashere employed, is not essential to the invention and further that thetemperature and thermoenergy consumption is far less than required forheat fusing in the absence of vapor. For example, though not in any wayto be regarded as an imitation, a temperature of about degreesFahrenheit is adequate to drive olf condensed vapor of thetrichloroethylene whereas for heat fusing, the web ordinarily attains atemperature on the order of approximately 240 degrees F.

Therefore, the elimination of vapor dragout, in accordance with theinvention, has resulted not only in a much lower dilution to theatmosphere, reducing ventilation requirements, annoying odors, etc., butalso the consumption of solvent attributable per unit of surface beingfused has been found to be substantially reduced. Thus, by means of theinstant invention ambient toxicity is so substantially reduced belowsafe levels that vapor fusing may now be used on commercial equipmentmore readily and more safely and in a more economical manner, while atthe same time, speeds previously unattainable and impractical for heatfusing or vapor fusing may now be effected by using a vapor fixingtechnique. This increased efficiency, therefore, produces both economic,comfort and speed advantages not enjoyed by the prior art devices suchas to provide a vapor fuser adapted for continuous operation with amoving web.

Since many changes can be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended all mattercontained in the drawings and specification shall be interpretedillustratively and not in a limiting sense.

What is claimed is:

1. In a xerographic apparatus including means to form a powder imagereproduction having a solvent soluble component loosely supported on acontinuous web support surface, and fusing means adapted to afx thepowder image substantially permanently onto said support surface, theimprovement comprising improved fusing means comprising in combination:

(a) a chamber substantially enclosed;

(b) vapor generating means in said chamber adapted to generate anatmosphere of solvent vapor of the solvent soluble component of thepowder image supported on the web;

(c) an opening defined in said chamber for the web to pass into saidatmosphere of vapor;

(d) a roll supported for rotation at least partially Within theatmosphere of vapor of said chamber spaced from said opening to receivethe continuous web supporting powder image reproductions in said vaporatmosphere for windup thereon into overlapping relation; and

(e) drive means adapted to rotate said roll to provide substantiallyuniform winding of the web there- 2. The improvement in the apparatusaccording to claim 1 including openable closure means forming part ofsaid chamber enclosure and means operative on power interruption to passsaid roll through said closure means substantially exterior of saidvapor chamber.

3. In a xerographic apparatus including means to form a powder imagereproduction having a solvent soluble component loosely supported on acontinuous web support surface, and fusing means adapted to afx thepowder image substantially permanently onto said support surface, theimprovement comprising improved fusing means comprising in combination:

(a) walls defining a substantially enclosed vapor chamber;

(b) a liquid solvent reservoir in said chamber adapted to containsolvent liquid of the solvent soluble component of the powder image;

(c) an opening dened in one wall for the web to pass into said chamber;

(d) a roll supported at least partially within said chamber and adaptedfor rotation to receive the continuous web supporting powder imagereproductions through said opening for windup thereon into overlappingrelation;

(e) wick means for generating a vapor of the solvent liquid in the pathof said web, said wick means being immersed at one end into liquidcontained in said reservoir and extending therefrom substantiallycontoured at least partially about the web from about the vicinity ofsaid opening until winding onto said roll; and,

(t) means enabling removal of said roll from its support after apredetermined length of web containing fused powder images has beenwound thereon.

4. The apparatus according to claim 3 in which said roll supports thewound web totally within said chamber.

5. The apparatus according to claim 4 including heating means exteriorof said chamber adapted to apply heat to vaporize absorbed solvent vaporprior to the web being overlapped upon.

6. In a Xerographic apparatus including means to form a powder imagereproduction having a solvent soluble component loosely supported on acontinuous web support surface, and fusing means adapted to aiiix thepowder image substantially permanently onto said support surface, theimprovement comprising improved fusing means comprising in combination:

(a) walls defining a substantially enclosed vapor chamber;

(b) a liquid solvent reservoir in said chamber adapted to containsolvent liquid of the solvent soluble cornponent of the powder image;

(c) a first opening dened in a wall for the web to pass into saidchamber;

(d) support means to support a power driven roll at least partiallywithin said chamber, said roll being adapted to rotate on the supportmeans to receive the continuous web supporting powder imagereproductions through said opening for windup thereon into overlappingrelation;

(e) wick means for generating a vapor of the solvent liquid in the pathof said web, said wick means being immersed at one end into liquidcontained in said reservoir and extending therefrom substantiallycontoured at least partially about the web from about the vicinity ofsaid rst opening until winding onto said roll;

(f) a seoond opening defined in a wall;

(g) closure means pressure -openable and adapted to close oi said secondopening; and,

(h) means connected to said roll support means operative in response toa power interruption to advance said roll through said second openingand said closure means to exterior of said chamber.

7. In a xerographic apparatus including means to form a powder imagereproduction having a solvent soluble component loosely supported on acontinuous web support surface, and fusing means adapted to atiix thepowder image substantially permanently onto said support surface, theimprovement comprising improved fusing means comprising in combination:

(a) walls defining a substantially enclosed vapor chamber;

(b) a liquid solvent reservoir in said chamber adapted to containsolvent liquid of the solvent soluble cornponent of the powder image;

(c) a rst opening deiined in a wall for the web to pass into saidchamber;

(d) support means to support a power driven roll at least partiallywithin said chamber, said roll being adapted to rotate on its supportmeans to receive the continuous web supporting powder imagereproductions through said opening for windup thereon int-o overlappingrelation;

(e) wick means for generating a Vapor of the solvent liquid in the pathof said web, said wick means being immersed at one end into liquidcontained in said reservoir and extending therefrom substantiallycontoured at least partially about the web from about the vicinity ofsaid lirst opening until winding onto said roll;

(f) a second opening defined in a wall;

(g) closure means pressure openable and adapted t-o t over said secondopening;

(h) seals about said closure means adapted to prevent vapor leakagethrough the tit of said closure means and said second opening; and,

(i) solenoid means connected to said roll support means operative inresponse to a power interruption to advance said roll through saidsecond opening and said closure means to exterior of said chamber.

References Cited bythe Examiner l UNITED STATES PATENTS 254,439 2/82Hyatt 34-153 X 2,271,192 1/42 Hinz lil7-63 X 2,562,182 7/51 Godley1l7-l07.1 2,702,760 2/55 Barth 117-107.1 2,726,166 l2/55 Greaves 117--212,776,907 11/57 Carlson 117-175 2,909,971 10/59 Barber 95-1.7 2,946,6827/60 Lauriello 96-1 2,947,625 8/60 Bertelsen 96-1 2,968,553 tl/6lGundlach 96-1 3,009,402 1l/6l Crumrine et al. 95 1.7 3,062,110 1l/62Shepardson et al. 95-l.7 3,132,047 5/64 Van Dorn 1117-21 X CHARLES AWILLMUTH, Primary Examiner.

NORMAN G. TORCHIN, WILLIAM D. MARTIN,

Examiners.

1. IN A XEROGRAPHIC APPARATUS INCLUDING MEANS TO FORM A POWDER IMAGEREPRODUCTION HAVING A SOLVENT SOLUBLE COMPONENT LOOSELY SUPPORTED ON ACONTINUOUS WEB SUPPORT SURFACE, AND FUSING MEANS ADAPTED TO AFFIX THEPOWDER IMAGE SUBSTANTAILLY PERMANENTLY ONTO SAID SUPPORT SURFACE, THEIMPROVEMENT COMPRISING IMPROVED FUSING MEANS COMPRISING IN COMBINATION:(A) A CHAMBER SUBSTANTAILLY ENCLOSED; (B) VAPOR GENERATING MEANS IN SAIDCHAMBER ADAPTED TO GENERATE AN ATMOSPHERE OF SOLVENT VAPOR OF THESOLVENT SOLUBLE COMPONENT OF THE POWDER IMAGE SUPPORTED ON THE WEB; (C)AN OPENING DEFINED IN SID CHAMBER FOR THE WEB TO PASS INTO SAIDATMOSPHERE OF VAPOR; (D) A ROLL SUPPORTED FOR ROTATION AT LEASTPARTAILLY WITHIN THE ATMOSPHERE OF VAPOR OF SAID CHAMBER SPACED FROMSAID OPENING TO RECEIVE THE